Drywall top-edge casing



Aug. 12, 1969 G. T. SOWINSKI DRYWALL TOP-EDGE CASING 2 Sheets-Sheet 1 Filed Oct. 3, 1967 INVENTOR. Gero rd T. Sowinski Aug. 12, 1969 7 G. T. SOWINSKI DRYWALL TOP-EDGE CASING 2 She'ets-Sheet'2 Filed Oct. 5, 1967 Fig.5

INVENTOR. Gerard T. Sowi nski ATTORNEY 3,460,298 DRYWALL TOP-EDGE CASING Gerard T. Sowinski, Lancaster, N.Y., assignor to National Gypsum Company, Buffalo, N.Y., a corporation of Delaware Filed Oct. 3, 1967, Ser. No. 672,656 Int. Cl. E04c 2/46 US. Cl. 52-98 1 Claim ABSTRACT OF THE DISCLOSURE An elongate metal channel having an opening equal to the thickness of gypsum wallboard, enclosing the top edge of gypsum wallboard and abutting the ceiling, having an elongate flange within the channel which is afiixed to the remainder of the channel by a relatively weak connection, whereby insertion of wall board into the channel by normal manual insertion forces is limited partway therein by the flange, but subsequent shifting or expansion forces will force the wall board further into the channel with failure of the weak connection.

BACKGROUND OF THE INVENTION It is known that subsequent to completion of building structures there are many ways in which the building, or portions thereof, move, as, for example, expansion and contraction of materials, settling of the structure, earth movements, etc. As a result the relationship between the floor, the sidewalls and the ceiling may change tending to create forces in the sidewalls which result in cracks in the walls. This is true in many kinds of wall construction, including the most common of walls, the drywall construction embodying a surface of gypsum wallboards. Many systems have been suggested to provide means for preventing cracking of drywall which have all generally met with one objection or another. For example, typical expansion joints have an obvious unnatural appearing opening or groove and are aesthetically undesirable. Compressible strips, placed between the top of a wall and a ceiling, bulge out when compressed.

SUMMARY OF THE INVENTION The present invention is directed to a novel channel member having some form of false bottom which is very weakly affixed to the remainder of the channel. This channel is manually placed on the top edge of wallboard. The false bottom prevents placing the board all the way into the channel. The channel is disposed against the ceiling and has the appearance of a finished trim element, with no obvious means showing for absorbing wall movement.

It is an object of the invention to provide an improved drywall metal casing and in particular a drywall casing having a weakly held false bottom therein.

It is a further object to provide an improved construction of drywall in combination with a ceiling and floor.

These and other objects and advantages of the invention will be more readily apparent when considered in relation to the preferred embodiments as set forth in the specification and shown in the drawings in which:

FIG. 1 is an isometric cross-sectional view of a wall, floor, and ceiling construction having a weak-false-bottom drywall casing at the wall top, which construction is in accordance with the present invention.

FIG. 2 is an isometric view of a modified form of construction of the wall top of FIG. 1.

FIG. 3 is an isometric view of the weak-false-bottom drywall casing of FIG. 1.

FIGS. 4 and 5 are isometric views of modified forms of weak-false-bottom drywall casings, embodying the present invention.

Referring to FIG. 1, there is shown a floor 10, a ceiling 12 and a wall 14 therebetween. Wall 14 includes a supporting stud 16, an elongate floor track 18, gypsum wallboards 20 on each side which form the well-known drywall exposed surfaces, floor trim 22, an elongate ceiling track 24 and an elongate weak-false-bottomed casing 26 disposed on the top edge 28 of each of the wall boards 20.

The floor track 18 and the ceiling track 24 are respectively aflixed to the floor 10 and ceiling 12 to form means for receiving the respective ends of studs 16. The studs 16 shown are metal studs, presently commonly used for screw attachment of gypsum wallboard. The studs 16 are inserted all the way down into the channel of floor track 18, and may be atfixed thereto as by a short screw 30.

The studs 16 extend only about halfway up into the channel of ceiling track 24 and are not firmly aflixed thereto. It will be preferable during partition erection if the stud dimensions are such as to provide friction lit within the ceiling track, however, after the wallboards 20 are aflixed to the studs 16, as by self-tapping screws 32, the studs will be held in position by the wallboards. The wall boards 20 are of substantially the same height as the studs 16 and the top edges 28 with the casing 26 thereon are disposed outside of the vertical sidewalls 34 of the ceiling track 24. In aflixing the wallboards 20 to studs 16, it is important that none of the screws 32 be any closer to the bottom edge of ceiling track sidewall 34 than about one inch.

In accordance with the invention, the casings 26 are basically elongate rigid channels, formed of metal or plastic, having a top wall 36, an inner sidewall 38, and an outer side wall 40. In the preferred embodiment shown, casing 26 includes two short flanges 42, 42 extending inwardly less than halfway, respectively from each of the two sidewalls 38, 40 and forming a false-bottom within the casing 26. The two flanges 42, 42 are purposely formed relatively weak, and easy to be broken off from sidewalls 38, 40-.

In constructing wall 14, wallboards 20 are cut to a height such that with the casing 26 placed on the wallboard top edge 28, with wallboard abutting flanges 42, 42, the wallboard with the casing 26 just fits between floor 10 and ceiling 12. The casing 26 has an opening width which provides a friction fit on the wallboard top edge 28. The wallboard 20, with the casing 26 is affixed to the studs 16, but none of them are affixed to the ceiling track 24. Accordingly, when building movement causes the ceiling 12 to move toward the floor 10, the ceiling track side wall 34 is free to move downward relative to the stud 16 and the wallboard 20. Simultaneously the ceiling 12 forces the casing 26 downward relative to the wallboard 20, the forces here involved being substantially greater than the manual force employed in originally placing the casing 26 on to the wallboard top edge 28. In forcing the casing 26 further onto wallboard 20, the weak flanges 42, 42 are broken off casing sidewalls 38, 40, and the wallboard top edge is then free to move up into casing 26 until the wallboard abuts the casing top wall 36.

After undergoing such movement, the exposed appearance of the partition will be unblemished, appearing as when new. A highly simplified wall construction is thus provided which permits of building movement, absorbing the effects of such movement with no effects of the movement showing on the surface.

FIGURE 2 shows an alternative form of constructing the top portion of the wall of the invention, wherein a thin sheet metal channel shaped casing bead 50 is disposed on the wallboard top edge 28, prior to manually placing the novel casing 26 thereon, thus strengthening the wallboard top edge 28 to lessen the potential of damage to the top edge 28 in the process of breaking otf of the weak flanges 42, 42 during building movement.

FIGURE 3 shows the preferred form of casing 26 enlarged, to clarify the means for making the flanges 42, 42 easy to break off properly. Each flange 42 is formed of a thickness generally throughout the flange which is greater than the thickness at the juncture 60 whereat the flange 42 joins the sidewalls 38 or 40. The break-01f of the flange 42, when it occurs, thus occurs at the most advantageous point, permitting the further movement of the wallboard top edge 28 into casing 26 with the least possibility of any damage or resistance to desired relative movement.

In FIGURE 4, a modified form of casing 70 is shown, wherein a weakly held flange 72 extends diagonally from the corner between a sidewall 74 and the top wall 76. Flange 72 is formed with a weakest, thinnest portion at the juncture 78 of the flange 72 with the sidewall and top wall corner. Flange 72 resists manual insertion of a wallboard top edge when about half-way inserted into the casing 70, but is not sufficiently strong to resist the forces of a building movement tending to force the casing 70 further onto the wallboard, whereby the flange 72 bends upward, with such greater force, until the flange is parallel to and abutting the top wall 76.

In FIGURE 5, a further modified form of casing 80' includes, as a separate element, a false bottom 82 weakly held between the casing sidewalls 84, and spaced from the casing top wall 86. Manual insertion of wallboard into casing 80 is limited by the false bottom 82, which however moves upward relative to the casing sidewalls 84 with the greater forces of a building movement.

Having completed a detailed disclosure of the preferred embodiments of my invention, so that others may practice the same, I contemplate that variations may be made.

I claim:

1. A building partition comprising wallboard, an expansion absorption casing, said casing comprising an elongate substantially rigid, open-bottomed channel having two sidewalls and a top wall, and a relatively Weakly-held false-bottom for stopping manual insertion of wallboard therein, spaced downwardly from said top wall, said casing being mounted on the top edge of said wallboard with said wallboard top edge abutting said relatively weaklyheld false-bottom, said casing being disposed against a ceiling-whereby on movement of said building said ceiling can move relatively toward said wallboard by said wallboard moving said false-bottom upwardly within said casing, said wallboard being aflixed to partition supporting studs of a height substantially equal to the height of said wallboard, said studs and said wallboard being substantially equally spaced from said ceiling whereby said ceiling can move relative to said studs and wallboard, said studs extending approximately halfway into a downwardly opening ceiling track, said wallboard top edge and said casing being disposed outwardly of said ceiling track, said ceiling track being vertically movable relative to said studs and said wallboard.

References Cited UNITED STATES PATENTS 3,292,328 12/1966 Lewis et al 52-238 3,363,390 1/1968 Crane et al 52-716 3,368,312 2/1968 Shore 52241 3,388,521 6/1968 Tillisch et al. 52241 X FRANK L. ABBOTT, Primary Examiner P. C. FAW, 1a., Assistant Examiner U.S. Cl. X.R. 

